Introduction

Emerald-MM-8Plus is a PC/104-Plus module with four or eight serial ports connected through the PCI bus. Each port supports RS-232, RS-422, RS-485 and 5V TTL interfaces using jumper configuration. The board also has eight digital I/O lines and a 16-bit counter/timer.

Emerald-MM-8Plus is connector compatible with the Emerald-MM-8P, Emerald-MM-8M, and Emerald-MM-8232 boards. It is compatible with all Diamond Systems Corporation CPUs with PC/104-Plus connectors. The board is intended to be compatible with any CPU with a PC/104-Plus expansion socket and operates with both 3.3V and 5V PCI I/O voltage buses.

Description and Features

Two I/O headers are provided, with four serial ports on each header. The board operates on +5V only, eliminating the need for a +12V supply that is often required for serial port operation.

Emerald-MM-8Plus is based on the Exar XR17D158IV Octal UART. This device contains eight identical sets of registers, one set for each port. The registers are compatible with the standard PC serial port. Each port contains a 64-byte FIFO.

The Emerald-MM-8Plus has the following features.

  • I/O connectors compatible with Emerald-MM-8P (two connectors, 40 pins, four ports per connector).

  • Eight serial ports based on Exar XR17D158IV Octal UART with 64-byte FIFOs.

  • RS-232, RS-422, RS-485, and TTL interfaces supported: RS-232/422/485 jumper selectable; TTL available as a custom assembly configuration.

  • Baud rates to 921.6Kbps in RS-232 or TTL mode, 1.8432Mbps in RS-422/RS-485 modes.

  • Jumper-selected protocol and line termination.

  • EEPROM storage of configuration data for instant availability on power-up.

  • I/O lines are short circuit protected.

  • Eight digital I/O lines with 5V logic.

  • LED connected to digital I/O line 0.

  • Programmable counter/timer with selectable clock source.

  • Dual 40-pin I/O headers, 4 ports per header.

  • +5V only operation.

  • Extended temperature (-40 to +85°C) operation.

  • PC/104-Plus form factor.

  • Stackthrough PC/104 and PC/104-Plus connectors installed.

    • Refer to the Exar XR17D158IV datasheet, listed in the Additional Information section of this document, for detailed information about using the UART, DIO and EEPROM functionality with the PC/104-Plus bus.

    Block Diagram

    Figure 1 shows the Emerald-MM-8Plus functional blocks.

    Figure 1: EMM-8Plus Functional Block Diagram




    Board Description

    Figure 2 shows the Emerald-MM-8Plus board connectors and jumpers.

    Figure 2: EMM-8Plus Board Layout




    Connector Summary

    The following tables list the Emerald-MM-8Plus board connectors.

    Connector Description Manufacturer Part No.
    J1 PC/104, ISA bus A,B EPT 962-60323-12B
    J2 PC/104, ISA bus C,D EPT 962-60203-12B
    J3 PC/104-Plus PCI bus connector -
    J4 Serial ports 1-4 -
    J5 Serial ports 5-8 -
    J15 Digital I/O and counter/timer -

    Jumper Summary

    The following table lists the Emerald-MM-8Plus jumpers.

    Jumper Description
    J6 PCI bus slot selection.
    J7-J10 Serial port configuration (Serial ports 1-4, respectively).
    J11-J14 Serial port configuration (Serial ports 5-8, respectively).